前言
在上一篇中我们完成了连接和发现服务两个动作，那么再发现服务之后要做什么呢？发现服务只是让你知道设备有什么服务，可以做什么事情。
正文
本篇要做的是显示服务下的特性，首先我们了解一下特性的基本知识。在蓝牙低功耗（BLE）中，特性（Characteristic）是蓝牙设备提供的一种数据单元，用于描述设备的某个属性或功能。特性包含了一系列的属性和值，可以用于读取、写入和通知数据。
BLE特性相关的关键概念和说明：
UUID（Universally Unique Identifier）：每个特性都会有一个唯一的UUID，用于标识该特性。值（Value）：特性包含一个值，可以是字节数组、字符串或其他数据类型。该值代表特性的当前状态或数据内容。属性（Properties）：特性具有一组属性，包括读、写、通知等。属性决定了可以对特性进行哪些操作。读（Read）：允许外部设备从特性中读取当前的值。写（Write）：允许外部设备向特性写入一个新的值。通知（Notify）：当特性的值发生变化时，可以通过通知方式将新的值发送给订阅该特性的外部设备。描述符（Descriptor）：特性可以附带一个或多个描述符，用于提供关于特性的额外信息或配置。
使用BLE特性，可以实现各种功能和数据交互，例如传感器数据的读取、设备状态的监控、远程控制等。特性的读写和通知操作可以通过与蓝牙设备的交互来实现。需要注意的是，BLE特性的操作和功能是由设备的厂商定义的，并在设备的GATT（Generic Attribute Profile）配置文件中进行描述。
首先理清一下思路，我们现在知道服务下面有特性，特性下面有一些属性值，其中属性（Properties）尤为重要，因为它决定了你的特性可以进行那些操作。用一个图来说明服务，特性，属性之间的关系。
一、获取属性列表
下面我们先获取最下面的属性，这是一个列表，属性值的处理有一些不同，首先我们在BleUtils中增加一个函数，代码如下所示：
/** * 获取属性 */ fun getProperties(property: Int): List<String> { val properties: MutableList<String> = ArrayList() for (i in 0..7) { when (property and (1 shl i)) { 0x01 -> properties.add("Broadcast") 0x02 -> properties.add("Read") 0x04 -> properties.add("Write No Response") 0x08 -> properties.add("Write") 0x10 -> properties.add("Notify") 0x20 -> properties.add("Indicate") 0x40 -> properties.add("Authenticated Signed Writes") 0x80 -> properties.add("Extended Properties") } } return properties }
这里是通过位运算进行计算属性的值，首先是循环遍历，shl 是一种位运算符，用于执行按位左移操作。shl 是 “shift left” 的缩写。and用于执行按位与操作。先左移再按位与，得到最终的值，根据得到属性描述，这些描述就是具体的功能操作。会返回一个属性列表，有了列表我们就可以写一个适配器了。
二、属性适配器
首先我们在layout下创建一个item_property.xml，代码如下所示：
<?xml version="1.0" encoding="utf-8"?> <TextView xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/tv_property" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginEnd="8dp" android:text="property" android:textColor="@color/orange" />
因为是String类型，所以我们就直接用一个TextView显示即可，下面我们写适配器，在adapter包下新建一个PropertyAdapter类，代码如下所示：
class PropertyAdapter( private val properties: List<String>, private val listener: OnItemClickListener ) : RecyclerView.Adapter<PropertyAdapter.ViewHolder>() { override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder { return ViewHolder(ItemPropertyBinding.inflate(LayoutInflater.from(parent.context), parent, false)).apply { binding.tvProperty.setOnClickListener { v -> listener.onItemClick(v, adapterPosition) } } } override fun onBindViewHolder(holder: ViewHolder, position: Int) { holder.binding.tvProperty.text = properties[position] } override fun getItemCount() = properties.size class ViewHolder(itemView: ItemPropertyBinding) : RecyclerView.ViewHolder(itemView.root) { var binding: ItemPropertyBinding init { binding = itemView } } }
这里进行了属性的点击监听，我们可以回调到特性适配器中去处理，下面我们要处理的就是特性了。
三、获取特性名称
首先是特性名称，同样是根据UUID，同样是那个PDF文档，在BleUtils中增加一个getCharacteristicsName()函数，代码有点多，如下所示：
/** * 获取特性名称 * @param uuid UUID */ fun getCharacteristicsName(uuid: UUID) = when ("0x${uuid.toString().substring(4, 8).uppercase(Locale.getDefault())}") { "0x2A00" -> "Device Name" "0x2A01" -> "Appearance" "0x2A02" -> "Peripheral Privacy Flag" "0x2A03" -> "Reconnection Address" "0x2A04" -> "Peripheral Preferred Connection Parameters" "0x2A05" -> "Service Changed" "0x2A06" -> "Alert Level" "0x2A07" -> "Tx Power Level" "0x2A08" -> "Date Time" "0x2A09" -> "Day of Week" "0x2A0A" -> "Day Date Time" "0x2A0C" -> "Exact Time 256" "0x2A0D" -> "DST Offset" "0x2A0E" -> "Time Zone" "0x2A0F" -> "Local Time Information" "0x2A11" -> "Time with DST" "0x2A12" -> "Time Accuracy" "0x2A13" -> "Time Source" "0x2A14" -> "Reference Time Information" "0x2A16" -> "Time Update Control Point" "0x2A17" -> "Time Update State" "0x2A18" -> "Glucose Measurement" "0x2A19" -> "Battery Level" "0x2A1C" -> "Temperature Measurement" "0x2A1D" -> "Temperature Type" "0x2A1E" -> "Intermediate Temperature" "0x2A21" -> "Measurement Interval" "0x2A22" -> "Boot Keyboard Input Report" "0x2A23" -> "System ID" "0x2A24" -> "Model Number String" "0x2A25" -> "Serial Number String" "0x2A26" -> "Firmware Revision String" "0x2A27" -> "Hardware Revision String" "0x2A28" -> "Software Revision String" "0x2A29" -> "Manufacturer Name String" "0x2A2A" -> "IEEE 11073-20601 Regulatory Certification Data List" "0x2A2B" -> "Current Time" "0x2A2C" -> "Magnetic Declination" "0x2A31" -> "Scan Refresh" "0x2A32" -> "Boot Keyboard Output Report" "0x2A33" -> "Boot Mouse Input Report" "0x2A34" -> "Glucose Measurement Context" "0x2A35" -> "Blood Pressure Measurement" "0x2A36" -> "Intermediate Cuff Pressure" "0x2A37" -> "Heart Rate Measurement" "0x2A38" -> "Body Sensor Location" "0x2A39" -> "Heart Rate Control Point" "0x2A3F" -> "Alert Status" "0x2A40" -> "Ringer Control Point" "0x2A41" -> "Ringer Setting" "0x2A42" -> "Alert Category ID Bit Mask" "0x2A43" -> "Alert Category ID" "0x2A44" -> "Alert Notification Control Point" "0x2A45" -> "Unread Alert Status" "0x2A46" -> "New Alert" "0x2A47" -> "Supported New Alert Category" "0x2A48" -> "Supported Unread Alert Category" "0x2A49" -> "Blood Pressure Feature" "0x2A4A" -> "HID Information" "0x2A4B" -> "Report Map" "0x2A4C" -> "HID Control Point" "0x2A4D" -> "Report" "0x2A4E" -> "Protocol Mode" "0x2A4F" -> "Scan Interval Window" "0x2A50" -> "PnP ID" "0x2A51" -> "Glucose Feature" "0x2A52" -> "Record Access Control Point" "0x2A53" -> "RSC Measurement" "0x2A54" -> "RSC Feature" "0x2A55" -> "SC Control Point" "0x2A5A" -> "Aggregate" "0x2A5B" -> "CSC Measurement" "0x2A5C" -> "CSC Feature" "0x2A5D" -> "Sensor Location" "0x2A5E" -> "PLX Spot-Check Measurement" "0x2A5F" -> "PLX Continuous Measurement" "0x2A60" -> "PLX Features" "0x2A63" -> "Cycling Power Measurement" "0x2A64" -> "Cycling Power Vector" "0x2A65" -> "Cycling Power Feature" "0x2A66" -> "Cycling Power Control Point" "0x2A67" -> "Location and Speed" "0x2A68" -> "Navigation" "0x2A69" -> "Position Quality" "0x2A6A" -> "LN Feature" "0x2A6B" -> "LN Control Point" "0x2A6C" -> "Elevation" "0x2A6D" -> "Pressure" "0x2A6E" -> "Temperature" "0x2A6F" -> "Humidity" "0x2A70" -> "True Wind Speed" "0x2A71" -> "True Wind Direction" "0x2A72" -> "Apparent Wind Speed" "0x2A73" -> "Apparent Wind Direction" "0x2A74" -> "Gust Factor" "0x2A75" -> "Pollen Concentration" "0x2A76" -> "UV Index" "0x2A77" -> "Irradiance" "0x2A78" -> "Rainfall" "0x2A79" -> "Wind Chill" "0x2A7A" -> "Heat Index" "0x2A7B" -> "Dew Point" "0x2A7D" -> "Descriptor Value Changed" "0x2A7E" -> "Aerobic Heart Rate Lower Limit" "0x2A7F" -> "Aerobic Threshold" "0x2A80" -> "Age" "0x2A81" -> "Anaerobic Heart Rate Lower Limit" "0x2A82" -> "Anaerobic Heart Rate Upper Limit" "0x2A83" -> "Anaerobic Threshold" "0x2A84" -> "Aerobic Heart Rate Upper Limit" "0x2A85" -> "Date of Birth" "0x2A86" -> "Date of Threshold Assessment" "0x2A87" -> "Email Address" "0x2A88" -> "Fat Burn Heart Rate Lower Limit" "0x2A89" -> "Fat Burn Heart Rate Upper Limit" "0x2A8A" -> "First Name" "0x2A8B" -> "Five Zone Heart Rate Limits" "0x2A8C" -> "Gender" "0x2A8D" -> "Heart Rate Max" "0x2A8E" -> "Height" "0x2A8F" -> "Hip Circumference" "0x2A90" -> "Last Name" "0x2A91" -> "Maximum Recommended Heart Rate" "0x2A92" -> "Resting Heart Rate" "0x2A93" -> "Sport Type for Aerobic and Anaerobic Thresholds" "0x2A94" -> "Three Zone Heart Rate Limits" "0x2A95" -> "Two Zone Heart Rate Limits" "0x2A96" -> "VO2 Max" "0x2A97" -> "Waist Circumference" "0x2A98" -> "Weight" "0x2A99" -> "Database Change Increment" "0x2A9A" -> "User Index" "0x2A9B" -> "Body Composition Feature" "0x2A9C" -> "Body Composition Measurement" "0x2A9D" -> "Weight Measurement" "0x2A9E" -> "Weight Scale Feature" "0x2A9F" -> "User Control Point" "0x2AA0" -> "Magnetic Flux Density - 2D" "0x2AA1" -> "Magnetic Flux Density - 3D" "0x2AA2" -> "Language" "0x2AA3" -> "Barometric Pressure Trend" "0x2AA4" -> "Bond Management Control Point" "0x2AA5" -> "Bond Management Feature" "0x2AA6" -> "Central Address Resolution" "0x2AA7" -> "CGM Measurement" "0x2AA8" -> "CGM Feature" "0x2AA9" -> "CGM Status" "0x2AAA" -> "CGM Session Start Time" "0x2AAB" -> "CGM Session Run Time" "0x2AAC" -> "CGM Specific Ops Control Point" "0x2AAD" -> "Indoor Positioning Configuration" "0x2AAE" -> "Latitude" "0x2AAF" -> "Longitude" "0x2AB0" -> "Local North Coordinate" "0x2AB1" -> "Local East Coordinate" "0x2AB2" -> "Floor Number" "0x2AB3" -> "Altitude" "0x2AB4" -> "Uncertainty" "0x2AB5" -> "Location Name" "0x2AB6" -> "URI" "0x2AB7" -> "HTTP Headers" "0x2AB8" -> "HTTP Status Code" "0x2AB9" -> "HTTP Entity Body" "0x2ABA" -> "HTTP Control Point" "0x2ABB" -> "HTTPS Security" "0x2ABC" -> "TDS Control Point" "0x2ABD" -> "OTS Feature" "0x2ABE" -> "Object Name" "0x2ABF" -> "Object Type" "0x2AC0" -> "Object Size" "0x2AC1" -> "Object First -Created" "0x2AC2" -> "Object Last - Modified" "0x2AC3" -> "Object ID" "0x2AC4" -> "Object Properties" "0x2AC5" -> "Object Action Control Point" "0x2AC6" -> "Object List Control Point" "0x2AC7" -> "Object List Filter" "0x2AC8" -> "Object Changed" "0x2AC9" -> "Resolvable Private Address Only" "0x2ACC" -> "Fitness Machine Feature" "0x2ACD" -> "Treadmill Data" "0x2ACE" -> "Cross Trainer Data" "0x2ACF" -> "Step Climber Data" "0x2AD0" -> "Stair Climber Data" "0x2AD1" -> "Rower Data" "0x2AD2" -> "Indoor Bike Data" "0x2AD3" -> "Training Status" "0x2AD4" -> "Supported Speed Range" "0x2AD5" -> "Supported Inclination Range" "0x2AD6" -> "Supported Resistance Level Range" "0x2AD7" -> "Supported Heart Rate Range" "0x2AD8" -> "Supported Power Range" "0x2AD9" -> "Fitness Machine Control Point" "0x2ADA" -> "Fitness Machine Status" "0x2ADB" -> "Mesh Provisioning Data In" "0x2ADC" -> "Mesh Provisioning Data Out" "0x2ADD" -> "Mesh Proxy Data In" "0x2ADE" -> "Mesh Proxy Data Out" "0x2AE0" -> "Average Current" "0x2AE1" -> "Average Voltage" "0x2AE2" -> "Boolean" "0x2AE3" -> "Chromatic Distance from Planckian" "0x2AE4" -> "Chromaticity Coordinates" "0x2AE5" -> "Chromaticity in CCT and Duv Values" "0x2AE6" -> "Chromaticity Tolerance" "0x2AE7" -> "CIE 13.3 - 1995 Color Rendering Index" "0x2AE8" -> "Coefficient" "0x2AE9" -> "Correlated Color Temperature" "0x2AEA" -> "Count 16" "0x2AEB" -> "Count 24" "0x2AEC" -> "Country Code" "0x2AED" -> "Date UTC" "0x2AEE" -> "Electric Current" "0x2AEF" -> "Electric Current Range" "0x2AF0" -> "Electric Current Specification" "0x2AF1" -> "Electric Current Statistics" "0x2AF2" -> "Energy" "0x2AF3" -> "Energy in a Period of Day" "0x2AF4" -> "Event Statistics" "0x2AF5" -> "Fixed String 16" "0x2AF6" -> "Fixed String 24" "0x2AF7" -> "Fixed String 36" "0x2AF8" -> "Fixed String 8" "0x2AF9" -> "Generic Level" "0x2AFA" -> "Global Trade Item Number" "0x2AFB" -> "Illuminance" "0x2AFC" -> "Luminous Efficacy" "0x2AFD" -> "Luminous Energy" "0x2AFE" -> "Luminous Exposure" "0x2AFF" -> "Luminous Flux" "0x2B00" -> "Luminous Flux Range" "0x2B01" -> "Luminous Intensity" "0x2B02" -> "Mass Flow" "0x2B03" -> "Perceived Lightness" "0x2B04" -> "Percentage 8" "0x2B05" -> "Power" "0x2B06" -> "Power Specification" "0x2B07" -> "Relative Runtime in a Current Range" "0x2B08" -> "Relative Runtime in a Generic Level Range" "0x2B09" -> "Relative Value in a Voltage Range" "0x2B0A" -> "Relative Value in an Illuminance Range" "0x2B0B" -> "Relative Value in a Period of Day" "0x2B0C" -> "Relative Value in a Temperature Range" "0x2B0D" -> "Temperature 8" "0x2B0E" -> "Temperature 8 in a Period of Day" "0x2B0F" -> "Temperature 8 Statistics" "0x2B10" -> "Temperature Range" "0x2B11" -> "Temperature Statistics" "0x2B12" -> "Time Decihour 8" "0x2B13" -> "Time Exponential 8" "0x2B14" -> "Time Hour 24" "0x2B15" -> "Time Millisecond 24" "0x2B16" -> "Time Second 16" "0x2B17" -> "Time Second 8" "0x2B18" -> "Voltage" "0x2B19" -> "Voltage Specification" "0x2B1A" -> "Voltage Statistics" "0x2B1B" -> "Volume Flow" "0x2B1C" -> "Chromaticity Coordinate" "0x2B1D" -> "RC Feature" "0x2B1E" -> "RC Settings" "0x2B1F" -> "Reconnection Configuration Control Point" "0x2B20" -> "IDD Status Changed" "0x2B21" -> "IDD Status" "0x2B22" -> "IDD Annunciation Status" "0x2B23" -> "IDD Features" "0x2B24" -> "IDD Status Reader Control Point" "0x2B25" -> "IDD Command Control Point" "0x2B26" -> "IDD Command Data" "0x2B27" -> "IDD Record Access Control Point" "0x2B28" -> "IDD History Data" "0x2B29" -> "Client Supported Features" "0x2B2A" -> "Database Hash" "0x2B2B" -> "BSS Control Point" "0x2B2C" -> "BSS Response" "0x2B2D" -> "Emergency ID" "0x2B2E" -> "Emergency Text" "0x2B2F" -> "ACS Status" "0x2B30" -> "ACS Data In" "0x2B31" -> "ACS Data Out Notify" "0x2B32" -> "ACS Data Out Indicate" "0x2B33" -> "ACS Control Point" "0x2B34" -> "Enhanced Blood Pressure Measurement" "0x2B35" -> "Enhanced Intermediate Cuff Pressure" "0x2B36" -> "Blood Pressure Record" "0x2B37" -> "Registered User" "0x2B38" -> "BR - EDR Handover Data" "0x2B39" -> "Bluetooth SIG Data" "0x2B3A" -> "Server Supported Features" "0x2B3B" -> "Physical Activity Monitor Features" "0x2B3C" -> "General Activity Instantaneous Data" "0x2B3D" -> "General Activity Summary Data" "0x2B3E" -> "CardioRespiratory Activity Instantaneous Data" "0x2B3F" -> "CardioRespiratory Activity Summary Data" "0x2B40" -> "Step Counter Activity Summary Data" "0x2B41" -> "Sleep Activity Instantaneous Data" "0x2B42" -> "Sleep Activity Summary Data" "0x2B43" -> "Physical Activity Monitor Control Point" "0x2B44" -> "Activity Current Session" "0x2B45" -> "Physical Activity Session Descriptor" "0x2B46" -> "Preferred Units" "0x2B47" -> "High Resolution Height" "0x2B48" -> "Middle Name" "0x2B49" -> "Stride Length" "0x2B4A" -> "Handedness" "0x2B4B" -> "Device Wearing Position" "0x2B4C" -> "Four Zone Heart Rate Limits" "0x2B4D" -> "High Intensity Exercise Threshold" "0x2B4E" -> "Activity Goal" "0x2B4F" -> "Sedentary Interval Notification" "0x2B50" -> "Caloric Intake" "0x2B51" -> "TMAP Role" "0x2B77" -> "Audio Input State" "0x2B78" -> "Gain Settings Attribute" "0x2B79" -> "Audio Input Type" "0x2B7A" -> "Audio Input Status" "0x2B7B" -> "Audio Input Control Point" "0x2B7C" -> "Audio Input Description" "0x2B7D" -> "Volume State" "0x2B7E" -> "Volume Control Point" "0x2B7F" -> "Volume Flags" "0x2B80" -> "Volume Offset State" "0x2B81" -> "Audio Location" "0x2B82" -> "Volume Offset Control Point" "0x2B83" -> "Audio Output Description" "0x2B84" -> "Set Identity Resolving Key" "0x2B85" -> "Coordinated Set Size" "0x2B86" -> "Set Member Lock" "0x2B87" -> "Set Member Rank" "0x2B88" -> "Encrypted Data Key Material" "0x2B89" -> "Apparent Energy 32" "0x2B8A" -> "Apparent Power" "0x2B8B" -> "Live Health Observations" "0x2B8C" -> "CO \\{} text-subscript { 2 } Concentration" "0x2B8D" -> "Cosine of the Angle" "0x2B8E" -> "Device Time Feature" "0x2B8F" -> "Device Time Parameters" "0x2B90" -> "Device Time" "0x2B91" -> "Device Time Control Point" "0x2B92" -> "Time Change Log Data" "0x2B93" -> "Media Player Name" "0x2B94" -> "Media Player Icon Object ID" "0x2B95" -> "Media Player Icon URL" "0x2B96" -> "Track Changed" "0x2B97" -> "Track Title" "0x2B98" -> "Track Duration" "0x2B99" -> "Track Position" "0x2B9A" -> "Playback Speed" "0x2B9B" -> "Seeking Speed" "0x2B9C" -> "Current Track Segments Object ID" "0x2B9D" -> "Current Track Object ID" "0x2B9E" -> "Next Track Object ID" "0x2B9F" -> "Parent Group Object ID" "0x2BA0" -> "Current Group Object ID" "0x2BA1" -> "Playing Order" "0x2BA2" -> "Playing Orders Supported" "0x2BA3" -> "Media State" "0x2BA4" -> "Media Control Point" "0x2BA5" -> "Media Control Point Opcodes Supported" "0x2BA6" -> "Search Results Object ID" "0x2BA7" -> "Search Control Point" "0x2BA8" -> "Energy 32" "0x2BA9" -> "Media Player Icon Object Type" "0x2BAA" -> "Track Segments Object Type" "0x2BAB" -> "Track Object Type" "0x2BAC" -> "Group Object Type" "0x2BAD" -> "Constant Tone Extension Enable" "0x2BAE" -> "Advertising Constant Tone Extension Minimum Length" "0x2BAF" -> "Advertising Constant Tone Extension Minimum Transmit Count" "0x2BB0" -> "Advertising Constant Tone Extension Transmit Duration" "0x2BB1" -> "Advertising Constant Tone Extension Interval" "0x2BB2" -> "Advertising Constant Tone Extension PHY" "0x2BB3" -> "Bearer Provider Name" "0x2BB4" -> "Bearer UCI" "0x2BB5" -> "Bearer Technology" "0x2BB6" -> "Bearer URI Schemes Supported List" "0x2BB7" -> "Bearer Signal Strength" "0x2BB8" -> "Bearer Signal Strength Reporting Interval" "0x2BB9" -> "Bearer List Current Calls" "0x2BBA" -> "Content Control ID" "0x2BBB" -> "Status Flags" "0x2BBC" -> "Incoming Call Target Bearer URI" "0x2BBD" -> "Call State" "0x2BBE" -> "Call Control Point" "0x2BBF" -> "Call Control Point Optional Opcodes" "0x2BC0" -> "Termination Reason" "0x2BC1" -> "Incoming Call" "0x2BC2" -> "Call Friendly Name" "0x2BC3" -> "Mute" "0x2BC4" -> "Sink ASE" "0x2BC5" -> "Source ASE" "0x2BC6" -> "ASE Control Point" "0x2BC7" -> "Broadcast Audio Scan Control Point" "0x2BC8" -> "Broadcast Receive State" "0x2BC9" -> "Sink PAC" "0x2BCA" -> "Sink Audio Locations" "0x2BCB" -> "Source PAC" "0x2BCC" -> "Source Audio Locations" "0x2BCD" -> "Available Audio Contexts" "0x2BCE" -> "Supported Audio Contexts" "0x2BCF" -> "Ammonia Concentration" "0x2BD0" -> "Carbon Monoxide Concentration" "0x2BD1" -> "Methane Concentration" "0x2BD2" -> "Nitrogen Dioxide Concentration" "0x2BD3" -> "Non -Methane Volatile Organic Compounds Concentration" "0x2BD4" -> "Ozone Concentration" "0x2BD5" -> "Particulate Matter - PM1 Concentration" "0x2BD6" -> "Particulate Matter - PM2.5 Concentration" "0x2BD7" -> "Particulate Matter - PM10 Concentration" "0x2BD8" -> "Sulfur Dioxide Concentration" "0x2BD9" -> "Sulfur Hexafluoride Concentration" "0x2BDA" -> "Hearing Aid Features" "0x2BDB" -> "Hearing Aid Preset Control Point" "0x2BDC" -> "Active Preset Index" "0x2BDD" -> "Stored Health Observations" "0x2BDE" -> "Fixed String 64" "0x2BDF" -> "High Temperature" "0x2BE0" -> "High Voltage" "0x2BE1" -> "Light Distribution" "0x2BE2" -> "Light Output" "0x2BE3" -> "Light Source Type" "0x2BE4" -> "Noise" "0x2BE5" -> "Relative Runtime in a Correlated Color Temperature Range" "0x2BE6" -> "Time Second 32" "0x2BE7" -> "VOC Concentration" "0x2BE8" -> "Voltage Frequency" "0x2BE9" -> "Battery Critical Status" "0x2BEA" -> "Battery Health Status" "0x2BEB" -> "Battery Health Information" "0x2BEC" -> "Battery Information" "0x2BED" -> "Battery Level Status" "0x2BEE" -> "Battery Time Status" "0x2BEF" -> "Estimated Service Date" "0x2BF0" -> "Battery Energy Status" "0x2BF1" -> "Observation Schedule Changed" "0x2BF2" -> "Current Elapsed Time" "0x2BF3" -> "Health Sensor Features" "0x2BF4" -> "GHS Control Point" "0x2BF5" -> "LE GATT Security Levels" "0x2BF6" -> "ESL Address" "0x2BF7" -> "AP Sync Key Material" "0x2BF8" -> "ESL Response Key Material" "0x2BF9" -> "ESL Current Absolute Time" "0x2BFA" -> "ESL Display Information" "0x2BFB" -> "ESL Image Information" "0x2BFC" -> "ESL Sensor Information" "0x2BFD" -> "ESL LED Information" "0x2BFE" -> "ESL Control Point" "0x2BFF" -> "UDI for Medical Devices" else -> "Unknown Characteristics" }
同修改一下原有的getServiceUUID()为getShortUUID()，只改名字而已，之前命名有点不太严谨。
四、特性适配器
首先我们在layout下创建一个item_characteristic.xml，代码如下所示：
<?xml ver
这里显示特性的名称和UUIID，同时加载属性列表，然后写适配器，因为需要操作属性的缘故，这些写一个接口，在adapter包下新建一个OperateCallback接口，代码如下所示：
interface OperateCallback { /** * 属性操作 */ fun onPropertyOperate(characteristic: BluetoothGattCharacteristic, operateName: String) }
通过这个接口可以知道当前操作的是那个特性和属性名称。下面我们写适配器，在adapter包下新建一个CharacteristicAdapter类，代码如下所示：
class CharacteristicAdapter( private val characteristics: List<BluetoothGattCharacteristic>, private val callback: OperateCallback ) : RecyclerView.Adapter<CharacteristicAdapter.ViewHolder>() { override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder { return ViewHolder(ItemCharacteristicBinding.inflate(LayoutInflater.from(parent.context), parent, false)) } override fun onBindViewHolder(holder: ViewHolder, position: Int) { holder.binding.tvCharacterName.text = BleUtils.getCharacteristicsName(characteristics[position].uuid) holder.binding.tvCharacterUuid.text = BleUtils.getShortUUID(characteristics[position].uuid) //加载特性下的属性 holder.binding.rvProperty.apply { layoutManager = LinearLayoutManager(context).apply { orientation = LinearLayoutManager.HORIZONTAL } val properties: List<String> = BleUtils.getProperties(characteristics[position].properties) adapter = PropertyAdapter(properties, object : OnItemClickListener { //点击属性 override fun onItemClick(view: View?, position: Int) { callback.onPropertyOperate(characteristics[position], properties[position]) } }) } } override fun getItemCount() = characteristics.size class ViewHolder(itemView: ItemCharacteristicBinding) : RecyclerView.ViewHolder(itemView.root) { var binding: ItemCharacteristicBinding init { binding = itemView } } }
在这里我们就可以处理特性的名称和UUID显示，同时加载属性适配器，显示出来。
五、加载特性
因为特性是在服务下的，所以我们可以在服务适配器中加载特性适配器。首先我们修改一下item_service.xml，代码如下所示：
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:orientation="vertical" android:background="@color/white" android:layout_height="wrap_content"> <androidx.constraintlayout.widget.ConstraintLayout android:id="@+id/item_service" android:layout_width="match_parent" android:foreground="?attr/selectableItemBackground" android:layout_height="wrap_content" android:orientation="vertical"> <TextView android:id="@+id/tv_service_name" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginStart="16dp" android:layout_marginTop="8dp" android:text="服务" android:textColor="@color/black" android:textSize="16sp" android:textStyle="bold" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/tv_uuid_title" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="UUID：" app:layout_constraintStart_toStartOf="@+id/tv_service_name" app:layout_constraintTop_toBottomOf="@+id/tv_service_name" /> <TextView android:id="@+id/tv_service_uuid" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="UUID" android:textColor="@color/black" app:layout_constraintBottom_toBottomOf="@+id/tv_uuid_title" app:layout_constraintStart_toEndOf="@+id/tv_uuid_title" app:layout_constraintTop_toTopOf="@+id/tv_uuid_title" /> <TextView android:id="@+id/tv_service_info" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginBottom="8dp" android:text="PRIMARY SERVICE" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintStart_toStartOf="@+id/tv_service_name" app:layout_constraintTop_toBottomOf="@+id/tv_uuid_title" /> <ImageView android:id="@+id/iv_state" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginEnd="16dp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintTop_toTopOf="parent" app:srcCompat="@drawable/ic_right_24" /> </androidx.constraintlayout.widget.ConstraintLayout> <androidx.recyclerview.widget.RecyclerView android:id="@+id/rv_characteristics" android:visibility="gone" android:layout_width="match_parent" android:layout_height="wrap_content" android:paddingStart="16dp" /> </LinearLayout>
整体上变化不大，只是加了一个RecyclerView，同时增加了一个ImageView，用于显示当前的服务是否展开，可以通过当前的服务item的方式控制是否显示特性列表，这里用到两个图标，在drawable下创建ic_right_24.xml，代码如下所示：
<vector xmlns:android="http://schemas.android.com/apk/res/android" android:width="24dp" android:height="24dp" android:tint="#000000" android:viewportWidth="24" android:viewportHeight="24"> <path android:fillColor="@android:color/white" android:pathData="M10,17l5,-5 -5,-5v10z" /> </vector>
还有一个ic_down_24.xml
<vector xmlns:android="http://schemas.android.com/apk/res/android" android:width="24dp" android:height="24dp" android:tint="#000000" android:viewportWidth="24" android:viewportHeight="24"> <path android:fillColor="@android:color/white" android:pathData="M7,10l5,5 5,-5z" /> </vector>
下面修改一下ServiceAdapter，代码如下所示：
class ServiceAdapter( private val services: List<BluetoothGattService>, private val callback: OperateCallback ) : RecyclerView.Adapter<ServiceAdapter.ViewHolder>() { override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder { val viewHolder = ViewHolder(ItemServiceBinding.inflate(LayoutInflater.from(parent.context), parent, false)) viewHolder.binding.itemService.setOnClickListener { //显示特性列表 viewHolder.binding.rvCharacteristics.visibility = if (viewHolder.binding.rvCharacteristics.visibility == View.VISIBLE) View.GONE else View.VISIBLE //更换图标 viewHolder.binding.ivState.setImageDrawable( if (viewHolder.binding.rvCharacteristics.visibility == View.VISIBLE) ContextCompat.getDrawable(parent.context, R.drawable.ic_down_24) else ContextCompat.getDrawable(parent.context, R.drawable.ic_right_24) ) } return viewHolder } override fun onBindViewHolder(holder: ViewHolder, position: Int) { holder.binding.tvServiceName.text = BleUtils.getServiceName(services[position].uuid) holder.binding.tvServiceUuid.text = BleUtils.getShortUUID(services[position].uuid) //加载服务下的特性 holder.binding.rvCharacteristics.apply { layoutManager = LinearLayoutManager(context) adapter = CharacteristicAdapter(services[position].characteristics, callback) } } override fun getItemCount() = services.size class ViewHolder(itemView: ItemServiceBinding) : RecyclerView.ViewHolder(itemView.root) { var binding: ItemServiceBinding init { binding = itemView } } }
和之前的区别就在于构造的时候增加了一个回调，并且在onCreateViewHolder()函数中就处理了服务Item的点击事件，而不是像之前一样回调到Activity中，在服务Item的点击事件中判断是否显示特性列表同时修改图标资源。最后再将接口回调到Activity中。
六、显示特性和属性
现在要做的就是修改MainActivity中的代码，首先修改activity_main.xml中的代码，主要是修改之前的rv_service中的属性值，修改后如下所示：
<androidx.recyclerview.widget.RecyclerView android:id="@+id/rv_service" android:layout_width="match_parent" android:layout_height="0dp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@+id/tv_device_info" />
主要就是让RecyclerView占满剩下的空间，避免内容过多导致无法滑动的情况，最后我们修改一下MainActivity中代码，如下所示：
class MainActivity : BaseActivity(), BleCallback, OperateCallback { ... override fun onServicesDiscovered(services: List<BluetoothGattService>) { runOnUiThread { mServiceList.clear() mServiceList.addAll(services) mServiceAdapter ?: run { mServiceAdapter = ServiceAdapter(mServiceList, this@MainActivity) binding.rvService.apply { (itemAnimator as SimpleItemAnimator).supportsChangeAnimations = false layoutManager = LinearLayoutManager(this@MainActivity) adapter = mServiceAdapter //增加分隔线 addItemDecoration(DividerItemDecoration(this@MainActivity, DividerItemDecoration.VERTICAL)) } mServiceAdapter } mServiceAdapter!!.notifyDataSetChanged() } } /** * 属性操作 */ override fun onPropertyOperate(characteristic: BluetoothGattCharacteristic, operateName: String) { showMsg(operateName) } }
修改的地方有三个，第一个就是MainActivity实现OnItemClickListener改成OperateCallback ，第二个是onServicesDiscovered()函数中，构建ServiceAdapter适配器中实现接口，然后添加分隔线，最后一个就是去掉之前onItemClick()函数改成onPropertyOperate()函数，运行一下看看效果。
七、源码
如果对你有所帮助的话，不妨 Star 或 Fork，山高水长，后会有期~
源码地址：GoodBle
